Working hand in hand with the Gambian National Malaria Control Programme (NMCP), MRC Unit The Gambia is at the forefront of research on malaria and on possible interventions for its control. Here, Unit Director Professor Umberto D’Alessandro provides an update on current work and future plans.
The Gambia has been extremely successful in reducing the burden of malaria, thanks to the scale-up of control interventions such as long-lasting insecticidal bed nets.
Some of the first studies on insecticide-treated bed nets were pioneered by The Unit in the late 1980s, and were followed by a study showing that insecticide-treated bed nets could dramatically reduce childhood mortality.
Our close collaboration with the NMCP has meant efficient translation of research findings into control measures. Evaluation following implementation of the national bed net programme by the NMCP in the early 1990s demonstrated that insecticide-treated bed nets resulted in an important reduction of mortality among children below 10 years of age. This result has been important not only for The Gambia but also for many other African countries.
Coverage of long-lasting insecticidal bed nets is currently very high thanks to the excellent work of the NMCP; this is one of the main reasons for the substantial decrease in childhood mortality and reduced number of malaria patients seen at health facilities over the last 10 years.
Over just two decades (1990-2008), annual under-5 mortality rates declined more than 70% – from 159 down to 45 per 1000 live births – resulting in attainment of Millennium Development Goal 4 seven years in advance of the target year of 2015.
The Unit was also involved in the evaluation of seasonal malaria chemoprevention, a monthly treatment (amodiaquine and sulfadoxine-pyrimethamine) given during the malaria transmission season to children 3-59 months old. The NMCP started implementing this intervention last year and it is expected to have an additional impact on the malaria burden.
Identifying hidden disease
Despite these successes, malaria transmission is still ongoing, more in the eastern than in the western part of The Gambia; the reasons for this difference are unknown. The major challenge is the hidden human reservoir of infection – individuals infected with malaria but not presenting with the classic symptoms associated with a clinical attack. These individuals are probably maintaining transmission, although we are unsure to what extent.
The scientific community generally believes that it will be extremely difficult to interrupt transmission with the tools and interventions currently available. In addition, the possible emergence and spread of drug and insecticide resistance threatens the current achievements in malaria control.
We are currently carrying out several research projects that may provide some of the solutions needed to interrupt malaria transmission. By investigating the dynamics of malaria transmission we hope to increase our understanding and find ways of interrupting transmission.
The main questions we are asking are: Who the carriers of malaria infection? and how are they contributing to the maintenance of transmission? Another of our projects is evaluating a treatment (primaquine) aimed at interrupting the transmission of infection from humans to mosquitoes.
We will increasingly invest in studies to find ways of interrupting malaria transmission in order to achieve malaria elimination. Such interventions may be new drugs, vaccines, or approaches such as targeted treatment of high-risk groups in order to decrease, and eliminate, the human reservoir of malaria.
Research is a major contributor to development and in the case of malaria it can help guide control efforts to decrease the malaria burden to extremely low levels and achieve disease elimination.
Here at MRC Unit The Gambia we are committed to research which will contribute to helping the NMCP to eliminate malaria. Researchers and implementers can, and should, work together to achieve this ambitious goal – for the elimination of malaria not only in The Gambia, but throughout the African continent.
Professor Umberto D’Alessandro
Unit Director, MRC Unit The Gambia